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Gunsmithing Melonite extending barrel life?

Re: Melonite extending barrel life?

Melonite is a case hardening process. The only major draw backs of it i have seen are chipping and cracking in your barrel will ruin it right quick. I have been playing with nitriding and so far it has been working perfectly. Ask jeffvn about it he is trying to burn a barrel out to test its affectiveness.
 
Re: Melonite extending barrel life?

Be interested in how this nitride testing turns out. Would like to have a way to make the throat in a 243 last longer.
 
Re: Melonite extending barrel life?

I haven't tried it YET, but am anxious to. I know of a benchrest shooter that had it done to a few barrels and has no complaints about the accuracy afterwards. It does case harden the surface substantially and I don't think there are any issues with warpage as it is in a molten bath of hot salts. Typically if heat is applied uniformly, warpage is not an issue on a concentric part (such as a barrel). I'm thinking of a 300 RUM long range hunting rifle that may benefit from such treatment, or possibly a 6.5-284.
 
Re: Melonite extending barrel life?

No matter what you do in order to extend your barrel life you will have to worry about heat not hardness. I know that the nitriding does take the heat better and dissapates it more as well. Warping is not a issue with this process they are still well below the melting point of the steel.
 
Re: Melonite extending barrel life?

It needs to be cheaper for me to consider it. For a few hundred dollars, I'd rather have my smith chamber up another barrel.
 
Re: Melonite extending barrel life?

I was under the impression it wasn't a good idea for actions due to the temperatures involved...upwards of 1100 degrees, which certainly would F* up the temper on a heattreated action... ?.
 
Re: Melonite extending barrel life?

Bobby is correct.

I have a 7mm barrel that has been treated that I'm about to install (I had to delay installation to use the rifle for a 1,000 yard F-Class match at the end of this month) on my current 7WSM for "testing" (that means I'll be doing lots of throat and velocity measuring, testing, and comparing with my 7WSM data from my current barrel that is on the rig). I've laid in plenty of powder and primers over the last year, so I'm ready to go on the testing.

The riflesmith that conviced me to try it has been working with several individuals that have each purportedly seen nearly 50% extended throat life and a 10-15% velocity gain. Given current barrel delivery times and installation costs, if it provides even 20% extended throat life and NO velocity gain - it will be worth the cost in my book.

I'm also planning on doing some similar testing on a different rifle in conjunction with Noel Carlson when I get the rifle delivered.

JeffVN
 
Re: Melonite extending barrel life?

Thanks Jeffvn, please post what you find. I agree that $150-200 is worth the extended life especially in something like a 7WSM.

I have been told that the melonite treatment is too tough to machine without excessively wearing the tooling and therefore needs to be applied after all machining and should be applied after the barrel was broken in. Are you planning on doing this?
 
Re: Melonite extending barrel life?

My dad and a friend messed with ceramic coatings in rifle barrels back in about 1985 but with only a small DIY shop they could never get a consistency in thickness that was conducive to good accuracy. It didn't flake or anything, but the 22-250 they were using to try it went from a MOA or better rifle to a 3 MOA rifle at 100 yards.

I'm sure new techniques and good quality control of a high grade ceramics place would do better now. It was interesting to read his notes on the process, his conclusion was "screw this, I'm going to buy more components and just go shooting"

I'd like to see the effect that some of the super hard, high temp Nitride type coatings would produce. Some of those are incredible under high sliding velocity applications, certainly which a rifle barrel is.
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: msalm</div><div class="ubbcode-body">I was under the impression it wasn't a good idea for actions due to the temperatures involved...upwards of 1100 degrees, which certainly would F* up the temper on a heattreated action... ?. </div></div>

Negative.
 
Re: Melonite extending barrel life?

Dont do an action. It will most likely soften the core material and have less strength. Be careful on bolts also. We have our bolts done, but they modify the process temperatures to accomodate our material.
 
Re: Melonite extending barrel life?

Sounds like you haven't tried this?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: stiller</div><div class="ubbcode-body">It will most likely soften the core material and have less strength. </div></div>

Why? Through a nitride rich bath in 1100 degs it get into the pores on the metal and hardens it to 70 on the C scale to at least .03" deep and can be taken deeper. What strength do you think your loosing?
 
Re: Melonite extending barrel life?

Just checked with 2 different metallurgists. They told me that it wont affect the core metal if it doesnt get hotter then the temper in the first place. 4140 is tempered at 1200 deg and 416 at 950. The SS would be done at a much lower temp for the nitrate.
 
Re: Melonite extending barrel life?

Tim8654, AZPrecision

I have my barrel and gas system on my M1A heat treated with the melonite treatment. It is not warped or chipping and seems to be wearing pretty good and it is pretty accurate so far. I have only put maybe 120 rounds through it so far.
 
Re: Melonite extending barrel life?

FWIW, We used Melonited barrels for several years in FCSA competition when we were shooting 12L14 Leadloy steel bullets. As mentioned above, the surface hardening allowed us to get upwards of 1000 rounds out of a barrel using the steel bullets. All machining had to be done ahead of time, and it was my understanding that it could only be done on CrMo steel, not 416R.
As Bobby mentioned, the barrel is still subject to heat crazing and eventually the lands would start fall apart in small chunks...

What I would like to see is if a barrel could be Titanium Nitride coated, as is done is some tooling. I don't know if if hardens below the surface at all, but it has a very low coefficient of friction. Very slippery stuff. Anyone????
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">Just checked with 2 different metallurgists. They told me that it wont affect the core metal if it doesnt get hotter then the temper in the first place. 4140 is tempered at 1200 deg and 416 at 950. The SS would be done at a much lower temp for the nitrate. </div></div>

That's the key. So long as the nitrided immersion temperature is lower than the temperature at which the part was tempered, you're golden.

As far as the lands crumbling, I'm sure that's not a problem with copper/lead bullets versus the steel bullets used in the .50 testing.

For a reference as to the durability of nitrided parts, I'll try getting a picture of the valvetrain in my race motor. 4 seasons at 8000 RPM with no measurable wear of the nitrided camshaft, versus a raw camshaft which typically wore in about .015" with 1 season in an equivalent arrangement.

-matt
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">Just checked with 2 different metallurgists. They told me that it wont affect the core metal if it doesnt get hotter then the temper in the first place. 4140 is tempered at 1200 deg and 416 at 950. The SS would be done at a much lower temp for the nitrate. </div></div>

This is basically true. If the temper temp is not exceeded, then it will not be affected. Most 4140 at 1200 deg F will have a rockwell in the lower 30's, too soft for an action and will tend to gall and have lug set back. Aim more for Rc 38 at about 1000 deg F. As for 416, it should never be tempered in a region between 750 and about 1050. It goes through a transition zone where the crystalline structure is brittle and crack propogation goes out of sight. Either stop at 700 or go past 1050. At 700 the toughness is the same as 1050 and Rc is about 42. At 1050 Rc goes to low 30's and will have the same issues as the 4140. Also, standard 416 without the R designation will have much more sulfur and can caused crack issues in the steel. Most 416R is a VAR processed material. Never use plain old cold or hot roll material as the properties are poor.

Most black iron nitrite (melonite) goes on at 1000 to 1200 deg F. We have our bolts done at 950. The place that does it is the only one we could find that would go that low.

My recommendation for anyone out there wanting to do any of these high temp processes better truly understand the heat treat conditions and the metallurgy that accompanies the processes. If not, a dangerous condition could easily show its ugly face.
 
Re: Melonite extending barrel life?

Jerry,

Understand about the actions, but have you done any barrels in addition to your bolts? Any results?

Thanks,

U2AV8R
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: stiller</div><div class="ubbcode-body">My coater is currently working on barrels and I have not yet done any. We have given him some 6 inch stubs to work out the process on. I have good hopes it will work well though. </div></div>

Please let us know what you find - especially interested in knowing if a treated barrel will last longer than an untreated one. Would do this to a new 243 to get some extra life out of it.
 
Re: Melonite extending barrel life?

Jerry,

Will you be fitting and chambering barrels before or after treatment? Or even after customer break-in. What do you envision the process to be?

Thanks for taking the time to contribute here.

U2AV8R
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: U2AV8R</div><div class="ubbcode-body">Jerry,

Will you be fitting and chambering barrels before or after treatment? Or even after customer break-in. What do you envision the process to be?

Thanks for taking the time to contribute here.

U2AV8R </div></div>

Everything must be done after its chambered. I have been suggesting people to do this before break in. If anything is left in the barrel wich you can do no matter how hard you try to clean it it could be very bad for the process. I have a few barrel that are in the process right now along with some dies. I will put my findings up as well.
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: stiller</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">Just checked with 2 different metallurgists. They told me that it wont affect the core metal if it doesnt get hotter then the temper in the first place. 4140 is tempered at 1200 deg and 416 at 950. The SS would be done at a much lower temp for the nitrate. </div></div>

This is basically true. If the temper temp is not exceeded, then it will not be affected. Most 4140 at 1200 deg F will have a rockwell in the lower 30's, too soft for an action and will tend to gall and have lug set back. Aim more for Rc 38 at about 1000 deg F. As for 416, it should never be tempered in a region between 750 and about 1050. It goes through a transition zone where the crystalline structure is brittle and crack propogation goes out of sight. Either stop at 700 or go past 1050. At 700 the toughness is the same as 1050 and Rc is about 42. At 1050 Rc goes to low 30's and will have the same issues as the 4140. Also, standard 416 without the R designation will have much more sulfur and can caused crack issues in the steel. Most 416R is a VAR processed material. Never use plain old cold or hot roll material as the properties are poor.

Most black iron nitrite (melonite) goes on at 1000 to 1200 deg F. We have our bolts done at 950. The place that does it is the only one we could find that would go that low.

</div></div>

Yes true. Depends on which type of tempering process you use. Tough to say unless you know.
 
Re: Melonite extending barrel life?

Got a barrel back today. Will be headed out shortly to see how it works. I also did some dies at the same time and they came out excellent. The finish is amazing and they work like butter.
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">Got a barrel back today. Will be headed out shortly to see how it works. I also did some dies at the same time and they came out excellent. The finish is amazing and they work like butter. </div></div>

Any update? Thanks.
 
Re: Melonite extending barrel life?

Yes there is. So far there is 500 rounds through the barrel and have seen no throat erosion or excessive craking. That was my main concern when doing this is was the harder barrel gonna put up with the heat. So far it looks great. I have a few 338/408 in the works and should be putting some rounds down them in the next few months. If anything will prove this processes worth it will be this caliber.
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">The only nitride coating i know of is a ion nitride. The TiN coating might build up. But i will be certan to ask a few people. </div></div>

Lammers is using a company that does salt bath nitride, is that the same as ion nitride? He's having some success with it as far as I know. Give him a buzz.
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: oneeyedmac</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">The only nitride coating i know of is a ion nitride. The TiN coating might build up. But i will be certan to ask a few people. </div></div>

Lammers is using a company that does salt bath nitride, is that the same as ion nitride? He's having some success with it as far as I know. Give him a buzz. </div></div>

Correct you are.
 
Re: Melonite extending barrel life?

John Pierce (http://www.pierceengineeringltd.com/) offers this service. There is a company somwhere in OH that does it for him.

I was extrememly skeptical the first time he was telling me about it, and the last thing you want to tell a smith/benchrest shooter is your skepticle.

He said "check this out", and brought me over to a brand new tube gun that was going to ship out to Creedmore sports. The barrel had just been istalled, and the melonite coating was a nice flat black color.

He picked up a big ass bastard cut file and drug it across the barrel, a brand new, never fired gun, for a customer that was about to ship....did not leave a mark. Now I am sure if you put pressure on it, it would sratch and do what a file is supposed to do, but just dragging it over the barrel did not leave a mark....I was in disbelief.

He says that many of his benchrest shooting buddies, including himself use it on their BR guns with excellant results, and barrel life doubling (BR barrel life mind you).

Its good stuff, if its the same that he uses...He did a 6.5x284 for a guy in CO (I think) that is around 4700 rounds (as of May) with no accuracy issues yet.

He is a guy that I trust more than anyone with rifle knowledge, and he says its stupid not to do it on a barrel. My next barrel will be melonited.
 
Re: Melonite extending barrel life?

I was talking to Mark Lammers at Losok recently, he has a lot of his stuff done in this finish. He had a barrel nitride finished prior to being finish chambered...oops. It took him a lot of effort to get throgh the stuff with the reamer and ended up having to have the reamer resharpened when he was done.
 
Re: Melonite extending barrel life?

i do alot of aftermarket HK barrels at my machine shop and have started nitriding all of the barrel we do. and poeple have been getting alot more life out of them. the nitride isn't that deep its just a surface hardness i think it is only .005" deep. and its not that expensive if you can get a batch together we pay by the lot not the individual barrel. also noticed that the place that does it for us has a gazillion sig saure barrels there getting nitrided
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: msalm</div><div class="ubbcode-body">I was under the impression it wasn't a good idea for actions due to the temperatures involved...upwards of 1100 degrees, which certainly would F* up the temper on a heattreated action... ?. </div></div>
4140 hardened and tempered bar can also be successfully nitrided, giving a surface hardness of up to Rc 60. Nitriding is carried out at 490 oC - 530 oC, followed by slow cooling (no quench) reducing the problem of distortion. Parts can therefore be machined to near final size, leaving a grinding allowance only. The tensile strength of the core is usually not affected since the nitriding temperature range is generally below the original tempering temperature employed.
 
Re: Melonite extending barrel life?

Because the surface becomes pretty slick have there been any reports of velocity changes?

I have had screws and some crossbow trigger parts coated in Melonite with out any issues. I did have one brand new AR barrel done and it shot for shit. I did not shoot the barrel before so I can not comment if it was the Melonite or not and have since been afraid to donate another barrel. A local smith who uses it on 1911 frames advicedme that he would not use it on a precion rifle barrel.

I have a local source that does a lot of work for S&W and other OEMs. I will contact them to see if I can get more information.
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: crossgun</div><div class="ubbcode-body">Because the surface becomes pretty slick have there been any reports of velocity changes?

I have had screws and some crossbow trigger parts coated in Melonite with out any issues. I did have one brand new AR barrel done and it shot for shit. I did not shoot the barrel before so I can not comment if it was the Melonite or not and have since been afraid to donate another barrel. A local smith who uses it on 1911 frames advicedme that he would not use it on a precion rifle barrel.

I have a local source that does a lot of work for S&W and other OEMs. I will contact them to see if I can get more information. </div></div>

Yes the couple i have seen and have had done show about 100 fps mininum gain. Depending on exactly how its done it has shown promise in the precision rifle market. I have a few that im getting done for myself to test soon. Cant wait to try to burn them out. If there are BR guys doing it and continuing to do it there's gotta be something good about it.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Policeman</div><div class="ubbcode-body">Isn't supposed to lower the corrosion resistance of SS? </div></div>

No around 300% more from what i understand.
 
Re: Melonite extending barrel life?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Niles Coyote</div><div class="ubbcode-body">HasgunWilltravel, did peirce advise what the service cost? </div></div>

Can not recall 100%, but think he saaid around $90..I am going to stop by and see john today, I will ask him.
 
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